中級閱讀模擬測驗　第二十二回

Every Sunday morning a group of neighbors walks along the beach with a large 11 in each hand. In two hours they usually collect forty kilos of 12: bottles, broken toys and old fishing nets. Most of it did not come from the town at all; the sea carries it here from far away. The volunteers do not simply 13 everything at the town's rubbish site. Plastic, glass and metal are sorted and sold, and the money buys gloves for the next walk. The leader says that people who once dropped 14 here now stop and think, because clean 15 change the way we behave.

For three days last winter the city disappeared behind a thick brown 16. Schools closed, and hospitals reported twice the usual number of 17 problems. The mayor acted at once. Old buses were taken off the road, factories were told to cut their 18 by half, and free masks were 19 at every station. Neighbors who had never met before began to share air readings on their phones. Since then the air is clearer, though far from clean. Scientists warn that some birds that once nested here may already be 20 in this valley, and that no law can bring them back.